Cartridge for exchangeably containing a disc

ABSTRACT

A cartridge for encasing a disc replaceably, including a cartridge body ( 2 ) having a write/read opening ( 24 ) formed in the bottom thereof, an inner rotor ( 4 ) rotatably received in the cartridge body ( 2 ) and having formed therein an opening ( 44 ) corresponding to the opening ( 24 ), and a pair of shutter members which uncovers the openings ( 24, 44 ) when the inner rotor ( 4 ) rotates until the openings ( 24, 44 ) are aligned with each other.

TECHNICAL FIELD

[0001] The present invention relates to a cartridge for replaceablyencasing a desired one of discs as information signal recording media ofdifferent diameters and permitting to load the recording medium encasedtherein into a recorder and/or player dedicated for disc cartridges.

BACKGROUND ART

[0002] If an optical disc as an information signal recording medium hasforeign matter such as dust, fingerprint or the like adherent to thesignal recording surface thereof, for example, information signal maynot possibly be recorded or reproduced accurately. On this account, theoptical disc of this type is usually encased in a cartridge body for useas a disc cartridge. For example, the optical disc is rotatably encasedin a cartridge body having a write/read opening. The cartridge body hasprovided therein shutter members to cover and uncover the write/readopening. The disc cartridge provided with the shutter members has theopening covered with the shutter members when it is not used in arecorder and/or player, to protect the optical disc held in thecartridge body. When the disc cartridge is loaded in the recorder and/orplayer, the shutter members are moved by a shutter releasing mechanismprovided in the recorder and/or player to uncover the write/readopening.

[0003] In the meantime, the optical discs include a one adopting arecording format in common to an optical disc pre-encased in a disccartridge and which can be loaded, being bare, namely, not being encasedin any cartridge, in a dedicated recorder and/or player to under gowrite or read of information signal.

[0004] However, in case one of the optical discs is loaded, encased in adisc cartridge, into a recorder and/or player while the other is loaded,not encased in any cartridge, into a recorder and/player, informationsignal cannot be written to, or read from, these two optical discs byany common recorder and/or player even if the optical discs adopt arecording format in common.

DISCLOSURE OF THE INVENTION

[0005] Accordingly, the present invention has an object to overcome theabove-mentioned drawbacks of the related art by providing a cartridgefor encasing a disc removably, and which permits to load itself havingencased therein a recording medium normally used bare, namely, notencased in any cartridge or the like, into a recorder and/or playerdedicated for a disc cartridge having a recording medium pre-encasedtherein.

[0006] The present invention has another object to provide a cartridgewhich can be assembled in generally same assembling steps as those for adisc cartridge, can easily be assembled, and which can encase a discremovably.

[0007] The present invention has still another object to provide acartridge capable of preventing a disc held in a disc receptacle fromcoming off, and which can encase a disc removably and protect the disc.

[0008] The present invention has yet another object to provide acartridge which can prevent a disc once encased therein from beingstained and/or damaged at the signal recording surface of the disc byrestricting easy insertion or removal of the disc.

[0009] The above object can be attained by providing a cartridgeincluding according to the present invention:

[0010] a cartridge body consisting of an upper shell having a discinsertion/removal opening formed in the main side thereof and a lowershell, butted to each other to define a disc receptacle in which a discis rotatably held, the lower shell having formed therein a first openingthrough which a disc held in the disc receptacle is at least partiallyexposed to output;

[0011] a middle shell disposed rotatably in the cartridge body to definethe bottom of the disc receptacle by the main side thereof, having themain side thereof exposed to outside through the insertion/removalopening in the upper shell, having formed in the main side thereof asecond opening corresponding to the first opening in the lower shell ofthe cartridge body and which is rotatably received in the cartridgebody; and

[0012] a pair of shutter members which uncovers the first and secondopenings when the middle shell rotates until the first and secondopenings are aligned with each other.

[0013] The above cartridge according to the present invention has auser's desired disc received in the disc receptacle through theinsertion/removal opening, and is loaded into a recorder and/or player.Since this cartridge is formed to have a similar construction includingthe shutter members, except for the insertion/removal opening formed inthe upper shell, to a disc cartridge of which the disc once encasedtherein cannot be replaced with another, so it can be loaded into arecorder and/or player dedicated for the recording-medium cartridge.

[0014] The above cartridge according to the present invention may havecome-off preventive mechanisms provided around the insertion/removalopening to prevent a disc received in the disc receptacle through theinsertion/removal opening from coming off. For example, each come-offpreventive mechanism is composed of a disc insertion guide to guide adisc being inserted into the disc receptacle and a come-off preventivepiece to prevent the disc once received in the fisc receptacle fromcoming off. The come-off preventive piece is formed integrally oncontact with elastically flexible pieces which are elastically movedradially of the disc receptacle. The come-off preventive mechanism maybe provided in a plurality of places around the insertion/removalopening to positively hold the disc in the disc receptacle.

[0015] The come-off preventive mechanisms provided in above cartridgeaccording to the present invention may be as will be described below.That is, each of the come-off preventive mechanisms includes a come-offpreventive member received in a receiver formed in the wall of theinsertion/removal opening in the upper shell to prevent a disc receivedin the disc receptacle from coming off. The come-off preventive memberincludes elastically flexible pieces each having an engagement portionformed at one end thereof, and an operating piece to move the come-offpreventive piece between a come-off preventive position where thecome-off preventive mechanism is to prevent the disc received in thedisc receptacle and an access position in which the disc is to beinserted and/or removed. Correspondingly, the receiver includes a firstengagement concavity in which the engagement portion is engaged when thecome-off preventive mechanism holds the come-off preventive member inthe come-off preventive position, and a second engagement concavity inwhich the engagement portion is engaged when the come-off preventivemechanism holds the come-off preventive member in the access position.The come-off preventive mechanism may be provided in a plurality ofplaces in order to prevent the disc from being caused by a wrongoperation to come off the disc receptacle.

[0016] Further, the above cartridge according to the present inventionmay be provided with a cover as a come-off preventive mechanism touncover and cover the insertion/removal opening. Also, the cartridge maybe provided with a locking mechanism to lock the cover in a closedposition. The locking mechanism has a cover operating member disposed inthe receiver formed in the wall of the insertion/removal opening in theupper shell. The cover operating member includes a first elasticallyflexible piece having provided at an end thereof a locking portion whichis engaged on the engagement piece on the cover, a second elasticallyflexible piece having an engagement portion provided at an end thereof,and an operating portion which moves the cover operating member betweena locking position in which the locking portion is engaged on theengagement piece and an unlocking position in which the locking portionis not disengaged on the engagement piece. Correspondingly, the receiverincludes a first engagement concavity in which the engagement portion isto be engaged when the cover operating member is held in the lockingposition, and a second engagement concavity in which the engagementportion is to be engaged when the cover operating member is held in theunlocking position. The locking mechanism may be provided in a pluralityof places around the insertion/removal opening in order to prevent thecover from being unlocked by a wrong operation, the cover from openingthe insertion/removal opening and thus the disc from coming off.

[0017] These objects and other objects, features and advantages of thepresent invention will become more apparent from the following detaileddescription of the best mode for carrying out the present invention whentaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is an exploded perspective view, from the upper shell, ofthe cartridge according to the present invention.

[0019]FIG. 2 is a perspective view, from the lower shell, of thecartridge shown in FIG. 1.

[0020]FIG. 3 is a perspective view, from the upper shell, of thecartridge shown in FIG. 1.

[0021]FIG. 4 is a plan view of the inside of the upper shell of thecartridge shown in FIG. 1.

[0022]FIG. 5 is a plan view of the inside of the lower shell of thecartridge shown in FIG. 1.

[0023]FIG. 6 is a perspective view of the inner rotor.

[0024]FIG. 7 is a perspective view, from another direction, of the innerrotor.

[0025]FIG. 8 is a plan view of the inner rotor in a position where itcovers the opening in the lower shell.

[0026]FIG. 9 is a plan view of the inner rotor in a position where ituncovers the opening in the lower shell.

[0027]FIG. 10 is a perspective view, from the upper shell, of the pairof shutter members.

[0028]FIG. 11 is a perspective view, from the lower shell, of the pairof shutter members.

[0029]FIG. 12 is a perspective view of the pair of shutter members in aposition where it uncovers the opening in the inner rotor.

[0030]FIG. 13 is a perspective view of the pair of shutter members in aposition where it covers the opening in the inner rotor.

[0031]FIG. 14 is a sectional view of the cartridge.

[0032]FIG. 15 is a plan view of the cartridge in which the pair ofshutter members covers the opening in the lower shell.

[0033]FIG. 16 is a segmentary sectional view of the cartridge, showingthat the lift-up projections of the inner rotor are engaged on those ofthe upper shell.

[0034]FIG. 17 is a perspective view of a recorder/player for use withthe cartridge.

[0035]FIG. 18 is an explanatory perspective view of the loader providedin the disc recorder/player in FIG. 17.

[0036]FIG. 19 is a perspective view of the shutter releasing member.

[0037]FIG. 20 is a plan view of the pair of shutter members beinginitially released.

[0038]FIG. 21 is a segmentary sectional view of the cartridge, showingthat the lift-up projections of the inner rotor are disengaged fromthose of the upper shell.

[0039]FIG. 22 is a plan view of the pair of shutter members with therack of the shutter releasing member being engaged with the gear of theinner rotor.

[0040]FIG. 23 is a plan view of the pair of shutter members in processof uncovering the opening.

[0041]FIG. 24 is a plan view of the pair of shutter members having fullyuncovered the opening.

[0042]FIG. 25 is a plan view of the cartridge with the optical disccome-off preventive mechanisms provided around the optical discinsertion/removal opening.

[0043]FIG. 26 is a segmentary plan view of the come-off preventivemechanism.

[0044]FIG. 27 is a segmentary sectional view of the come-off preventivemechanism.

[0045]FIG. 28 is a plan view of the cartridge with the optical disccome-off preventive mechanisms provided around the optical discinsertion/removal opening.

[0046]FIG. 29 is a segmentary plan view of the optical disc come-offpreventive mechanism.

[0047]FIG. 30 is a segmentary sectional view of the optical disccome-off preventive mechanism.

[0048]FIG. 31 is a plan view of the cartridge provided with a cover.

[0049]FIG. 32 is a side elevation of the cartridge with the optical discinsertion/removal opening being uncovered with the cover opened.

[0050]FIG. 33 is a segmentary plan view of the locking mechanism in aposition where it locks the cover.

[0051]FIG. 34 is a segmentary plan view of the locking mechanism in aposition where it unlocks the cover.

[0052]FIG. 35 is an exploded perspective view of a variant of thecartridge according to the present invention.

[0053]FIG. 36 is a perspective view, from below, of the cartridge inFIG. 35.

[0054]FIG. 37 is a perspective view of the cartridge in FIG. 36 with thepair of shutter members being released to uncover the opening.

BEST MODE FOR CARRYING OUT THE INVENTION

[0055] The cartridge according to the present invention will beexplained herebelow with reference to the accompanying drawings.

[0056] The cartridge according to the present invention is generallyindicated with a reference 1 through FIGS. 1 to 3. It is used as a caddyfor encasing an optical disc therein. As shown in FIGS. 1 to 3, thecartridge 1 houses a cartridge body 2 incorporates an optical disc 3 asa recording medium, an inner rotor 4 serving as a middle shell, and apair of shutter members 5 a and 5 b. The cartridge body 2 consists of apair of shells, upper and lower, 6 and 7, combinable with each other.

[0057] As shown in FIG. 2, the optical disc 3 received removably in thecartridge 1 has the same diameter, 12 cm, a CD (compact disc) or DVD(digital versatile disc) for example. It has formed in the centerthereof a hole 3 in which a part of the disc rotation drive mechanism ofa recorder/player. The optical disc 3 is made of a synthetic resin-madesubstrate having a predetermined pattern of lands and grooves formed onone side thereof, and includes a reflective layer formed over thepredetermined pattern on the substrate to reflect a light beam, a signalrecording layer formed, over the reflective layer, from a phase-changematerial, organic dye recording material or the like, and alight-transmissive layer formed over the signal recording layer. Thus, alight beam is projected from the light-transmissive layer side to theoptical disc 3 to record data in the form of such lands and/or grooves.More specifically, a light beam of about 400 nm in wavelength is used towrite or read data to the optical disc 3 and the optical pickup of therecorder/player uses an objective lens having a larger numericalaperture (NA) than that of an objective lens used for a CD or DVD,whereby data such as still image data, moving image data, music data,computer-processible data, etc. can be recorded to the optical disc 3.

[0058] The discs as a recording medium, which can be encased in thecartridge 1, includes a magneto-optical disc, magnetic disc or the like.Also, the disc may also be a read-only optical disc.

[0059] As shown in FIG. 4, the upper shell 6 is formed by injectionmolding of a thermoplastic synthetic resin such as acrylonitrilebutadiene styrene (ABS) for example. The upper shell 6 is formed to havea generally rectangular shape of which the front end which will be firstinserted into the recorder/player is shaped like a generally circulararc. The upper shell 6 has formed integrally therewith an outer wall 8rising from the perimeter of the main side and which defines the lateralface of the cartridge body 2.

[0060] The outer wall 8 has formed, by cutting, in the front centerthereof a first pickup access opening 9 into which the optical pickup ofthe recorder/player 70 can be brought. Also, the outer wall 8 hasformed, by cutting, in the rear center thereof a positioning concavity10 with reference to which the upper shell 6 is positioned in relationto the lower shell 7.

[0061] Further, the upper shell 6 has formed therein a generallycircular opening whose wall 11 is inscribed in the outer wall 8 andthrough which the optical disc 3 is inserted or removed. The wall 11 ofthe insertion/removal opening (will be referred to as “opening wall”hereunder) defines a disc receptacle in which the optical disc 3 isrotatably received. The opening wall 11 has formed, by cutting, in thefront center thereof a second pickup access opening 12 into which anoptical pickup 75 of the recorder/player 70 which will be described indetail later is to be brought. As shown in FIG. 14, the opening wall 11defines together with the main side of an inner rotor 4 which will bedescribed in detail later a disc receptacle 11 a in which the opticaldisc 3 is rotatably received.

[0062] Between the opening wall 11 and outer wall 8, there is formed arising wall to surround the opening wall 11. The opening wall 11 andrising wall define together a generally circular guide recess 13 inwhich the inner rotor 4 is rotatably engaged. The guide recess 13 hasformed on the bottom thereof in the front center and rear center a pairof lift-up projections 14 which will move the inner rotor 4 away fromthe upper shell 6.

[0063] As shown, the upper shell 6 has four corners 6 a, 6 b, 6 c and 6d. Of these corners, one front corner 6 a forms a locking memberreceiver in which a locking member to lock the shutter members 5 a and 5b is received. At the other corners 6 b, 6 c and 6 d, there are formedrising upper corner walls 15, respectively, which prevent dust fromentering the cartridge inside. Each of the upper corner walls 15 isdefined between the outer wall 8 and guide recess 13. A first recess 16is formed between each upper corner wall 15 and outer wall 8, and asecond recess 17 is defined between the upper corner wall 15 and guiderecess 13.

[0064] The upper shell 6 has formed at the rear corner 6 c thereof anupper rising wall 18 defining a write protection member receiver inwhich a write protection member is held. A third recess 19 is definedbetween the upper rising wall 18 and upper corner wall 15.

[0065] The upper shell 6 has formed near each of the corners 6 a, 6 b, 6c and 6 d thereof a positioning pin 20 for coupling to the lower shell7. Each of the positioning pin 20 has formed in the center thereof ascrewing hole.

[0066] As shown in FIGS. 1, 2 and 4, the upper shell 6 has formed in themain side thereof the disc insertion/removal opening 2 a for replacementof the optical disc 3 held in the disc receptacle 11 a. For smoothinsertion or removal of the optical disc 3, the insertion/removalopening 2 a is formed to have a little larger diameter than the diameterof the optical disc 3. More specifically, the insertion/removal opening2 a is defined by the opening wall 11 of the upper shell 6.

[0067] As shown in FIGS. 2, 3 and 5, the lower shell 7 to be coupled tothe upper shell 6 constructed as having been described above is formedby injection molding of a thermoplastic synthetic resin such asacrylonitrile butadiene styrene (ABS) for example similarly to theaforementioned upper shell 6. The lower shell 7 is formed to have a mainside thereof shaped generally rectangular, whose front end which willfirst be inserted into the recorder/player is formed to have a generallycircular arc shape. The lower shell 7 has formed integrally therewith anouter wall 21 protruding from the perimeter of the main side and whichalso defines the lateral face of the cartridge body 2.

[0068] The outer wall 21 has formed at the rear side thereof apositioning wall 22 which is engaged in the aforementioned positioningconcavity 10 of the upper shell 6 to align the upper and lower shells 6and 7 with each other. Also, the outer wall 21 has formed at the rearside thereof a dustproof wall 23 which is engaged in the first recess 16of the upper shell 6 to prevent dust or the like from entering thecartridge from between the upper and lower shells 6 and 7.

[0069] The lower shell 7 has formed in the front center of the outerwall 21 an opening 24 into which the optical pickup and disc table canbe brought. The opening 24 is defined by a generally rectangularwrite/read opening 24 a through which the signal recording surface ofthe optical disc 3 is partially exposed to outside in a range from thefront open end to the inner circumference of the disc, and a discrotation drive opening 24 b contiguous to the write/read opening 24 aand through which the central hole 3 a in the optical disc 3 is exposedto outside. More specifically, the write/read opening 24 a is formed tohave sufficient dimensions to bring the optical pickup of therecorder/player to a depth of the cartridge body 2, and the discrotation drive opening 24 b is formed to have sufficient dimensions tobring the disc table include in the disc rotation drive mechanism of therecorder/player 70 can be brought to a depth of the cartridge body 2.

[0070] The lower shell 7 has four corners 7 a, 7 b, 7 c and 7 d. At onefront corner 7 a of these corners, forming the locking member receiver,there is formed a projecting pivot 25 to support the locking member 29pivotably. At the other corners 7 b, 7 c and 7 d except for the frontcorner 7 a, there are formed generally arc-shaped lower corner walls 26,respectively, which are to be engaged in the second recesses 17,respectively, at the aforementioned upper shell 6. Further, at one rearcorner 7 c, there is formed a rising lower wall 27 which is to beengaged in the third recess 19 at the upper shell 6. The lower shell 7has formed thereon a generally cylindrical positioning cap 28 which isto be fitted on the positioning pin 20 at the upper shell 6. Thepositioning cap 28 has formed in the center thereof a through-holethrough which a set screw is penetrated.

[0071] For coupling the upper and lower shells 6 and 7 to each other,the positioning wall 22 at the lower shell 7 is engaged in thepositioning concavity 10 at the upper shell 6, the positioning cap 28 atthe lower shell 7 is fitted on the positioning boss 20 at the uppershell 6, and the dustproof wall 23, lower corner wall 26 and risinglower wall 27 at the lower shell 7 are engaged in the first, second andthird recesses 16, 17 and 19, respectively, at the upper shell 6. A setscrew is screwed into the screw hole in the positioning boss 20 throughthe through-hole in the positioning cap 28.

[0072] As shown in FIG. 14, when the upper and lower shells 6 and 7 aresuperposed on each other, the cartridge body 2 will have defined by theopening wall 11 and main side of the inner rotor 4 the disc receptacle11 a almost inscribing the perimeter of the cartridge body 2, alsodefined at one front corner thereof the locking member receiver in whichthe locking member 29 is pivotably held, and further defined at one rearcorner thereof the receiver in which a write protection member 30 isslidably held.

[0073] When the inner rotor 4 is in a position where it covers theopening 24 in the cartridge body 2, the locking member 29 locks theinner rotor 4 against rotation. As shown in FIG. 2, the locking member29 includes an engagement hole 31 in which the pivot 25 of the lowershell 7 is rotatably engaged, an operating piece 32 extending from theengagement hole 31 toward one lateral side of the cartridge body 2, astop piece 33 extending from the engagement hole 31 toward the discreceptacle 11 a, and a spring piece 34 extending from the engagementhole 31 toward the front inner wall of the cartridge body 2. Theoperating piece 32 has provided at the end thereof an operatingprojection 32 a projected to outside through a locking opening 35 aformed in one lateral side of the cartridge body 2. The stop piece 33has provided at the end thereof a stop projection 33 a sliding on a ringportion 43 of the inner rotor 4. The spring piece 34 abuts, in anelastically deformed shape, the front inner side of the cartridge body2. Therefore, the spring piece 34 forces, by its elasticity, the openingprojection 32 a of the operating piece 32 in a direction of projectingout of the locking opening 35 a, and the stop projection 33 a of thestop piece 33 in a direction of abutting the ring portion 43 of theinner rotor 4 and engagement into a second engagement concavity 42 ofthe inner rotor 4. When the operating projection 32 a of the operatingpiece 32 of the locking member 29 is pressed, the stop piece 33 movedagainst the elasticity of the spring piece 34 away from the ring portion43 of the inner rotor 4. Since the locking member 29 is moved away fromthe ring portion 43, the stop projection 33 a is disengaged from thesecond engagement concavity 42.

[0074] When operated along the back of the cartridge body 2, the writeprotection member 30 can be moved along the back of the cartridge body 2between a “writing possible” position where it uncovers an access holeand a “data protected” position where it covers the access hole, forexample.

[0075] As shown in FIG. 3, the cartridge body 2 has a guide recess 36formed on one lateral side thereof to extend from the front to back ofthe cartridge body 2. This guide recess 36 is provided to prevent thecartridge 1 from being inserted incorrectly into the recorder/player. Inthe bottom of the guide recess 36, there are formed a locking opening 35a through which the aforementioned operating projection 32 a of thelocking member 29 is projected to outside and an inner rotor accessopening 35 b through which the inner rotor 4 is exposed partially at theperimeter thereof to outside. As shown in FIG. 3, in the bottom of thecartridge body 2, formed by the lower shell 7, there is formed aplurality of positioning concavities 38 to position the cartridge 1 whenloaded in the recorder/player 70. Also, on either lateral side of thecartridge body 2, there is formed a plurality of cuts 39 for positioningthe cartridge 1 when loaded in the recorder/player and identification ofthe type of a disc cartridge.

[0076] As shown in FIGS. 6 and 7, the inner rotor 4 is formed byinjection molding of a thermoplastic synthetic resin such aspolyoxymethylene (POM) for example. When the inner rotor 4 is placedinside the cartridge body 2, it will define the disc receptacle 11 a bythe main side thereof and opening wall 11 of the upper shell 6 as shownin FIG. 14. The inner rotor 4 is formed to have a generally circularshape whose perimeter is formed as the rising ring portion 43 which isengaged in the aforementioned guide recess 13 of the upper shell 6. Withthe ring portion 43 engaged in the guide recess 13 of the upper shell 6,the inner rotor 4 is pivotably supported by the cartridge body 2. Theinner rotor 4 has formed therein an opening 44 which is generally thesame in dimensions as the opening 24 formed in the lower shell 7. Acoupling 43 a is provided to connect, as a bridge, the ends, cut by theopening 44, of the ring portion 43.

[0077] The ring portion 43 has formed on the outer periphery thereof ageared portion 45 which rotates the inner rotor 4. The gear portion 45extends between a position where the inner rotor 4 is exposed partiallyat the perimeter thereof to outside through the front portion of theinner rotor access opening 35 b when it covers the opening 24 in thelower shell 7 as shown in FIG. 8, and a position where the inner rotor 4is exposed partially at the perimeter thereof to outside through therear portion of the inner rotor access opening 35 b when it uncovers theopening 24 in the lower shell 7 as shown in FIG. 9.

[0078] Also, the inner rotor 4 has formed on the outer periphery thereofat one side of the geared portion 45 a first engagement concavity 41 inwhich a first engagement projection of a shutter releasing memberincluded in a shutter release mechanism at the recorder/player, and atthe other side of the geared portion 45 a second engagement concavity 42in which a second engagement projection of the shutter releasing memberis engaged. These engagement concavities 41 and 42 are exposed alongwith the geared portion 45 to outside through the inner rotor accessopening 35 b. When the cartridge 1 is loaded into the recorder/player,the first engagement concavity 41 has first engaged therein the firstengagement projection of the shutter releasing member. When the pair ofshutter members 5 a and 5 b is in the closed position, the secondengagement concavity 42 has engaged therein the stop projections 33 a ofthe locking member 29. When the pair of shutter members 5 a and 5 bmoved to the position where it uncovers the openings 24 and 44, thesecond engagement concavity 42 will receive the second engagementprojection of the shutter releasing member.

[0079] The ring portion 43 has a pair of rotation limiting projections46 a and 46 b formed spaced a predetermined interval on the outerperiphery thereof to limit the rotation of the inner rotor 4. On theother hand, the upper shell 6 has formed between the guide recess 13 andupper corner wall 15 a pair of limiters 47 a and 47 b which abut thepair of inner-rotor rotation limiting projections 46 a and 46 b,respectively. As shown in FIG. 9, when the inner rotor 4 rotates in adirection of uncovering the opening 24, one of the rotation limitingprojections (46 a) abuts one of the pair of limiters (47 a) to prevent afurther rotation of the inner rotor 4. When the inner rotor 4 is thuslimited from rotating in this direction, it is in a position where ituncovers the opening 24 and the opening 44 in the inner rotor 4 isnearly aligned with the opening 24 in the cartridge body 2. On the otherhand, as shown in FIG. 8, when the inner rotor 4 rotates in a directionof covering the opening 24, the other inner-rotor rotation limitingprojection 46 b abuts the other limiter 47 b to prevent a furtherrotation of the inner rotor 4. When the inner rotor 4 is limited againstrotation in this direction, it is in a position where it covers theopening 24 and the opening 44 in the inner rotor 4 is most inclined inrelation to the opening 24 of the cartridge body 2.

[0080] As shown in FIGS. 8 and 9, the ring portion 43 has formed thereona pair of lift-up projections 48 which slide on the aforementioned pairof lift-up projections 14 formed on the bottom of the guide recess 13.When the inner rotor 4 is close to the position where it covers theopening 24, the lift-up projections 48 slide onto the lift-upprojections 14, respectively, in the guide recess 13 and thus lift upthe inner rotor 4 away from the upper shell 6.

[0081] As shown in FIGS. 6 to 9, the inner rotor 4 has formed on themain side thereof opposite to that on which the ring portions 43 areformed a pair of projecting pivots 49 a and 49 b which support the pairof shutter members 5 a and 5 b rotatably. The pair of pivots is locatedin positions, respectively, symmetrical with the center of the innerrotor 4, that is, 180 deg. out of phase from each other.

[0082] As shown in FIGS. 10 and 11, the shutter members 5 a and 5 bplaced on the above inner rotor 4 to cover and uncover the openings 44and 44 a in the inner rotor 4 have symmetrical shapes and are installedon the pair of pivots 49 a and 49 b, respectively, of the inner rotor 4to be pivotable with a phase difference of 180 deg. between them. Itshould be noted that since the pair of shutter members 5 a and 5 b havemany identical parts, they will collectively be referred to simply as“shutter member 5” and also the identical parts will be indicated withthe same references, respectively.

[0083] Similarly to the inner rotor 4, the shutter members 5 a and 5 bare formed by injection molding of a thermoplastic synthetic resin suchas polyoxymethylene (POM) for example. The shutter member 5 is formed tohave a generally meniscal shape whose base portion has formed therein anengagement hole 50 a or 50 b in which the aforementioned pivot 49 a or49 b of the inner rotor 4 is pivotably engaged.

[0084] Also, each of the shutter members 5 a and 5 b has formed on thestring-like butting face thereof a first engagement potion 51 extendingfrom the central portion toward the base and a second engagement portion52 extending from the central portion toward the free end. Of the firstand second engagement portions, the first one 51 is beveled at the sideof the lower shell 7, while the second engagement portion 52 is beveledat the side of the upper shell 6. As shown in FIGS. 12 and 13, theshutter members 5 a and 5 b in pair are pivoted about the pivots 49 aand 49 b, respectively, on the inner rotor 4 toward or away from eachother, the first engagement portion 51 of one of the shutter members (5a) engages on the second engagement portion 52 of the other shuttermember 5 b, while the first engagement portion 51 of the other shuttermember 5 b engages on the second engagement portion 52 of the oneshutter member 5 a.

[0085] Each of the shutter members 5 a and 5 b has formed therein aguide slot 54 in which one of a pair of guide pins 53 formed on theinner surface of the lower shell 7 shown in FIG. 5. The guide slot 54extends over a predetermined length from the midpoint of the string-likebutting face toward the engagement hole 50 a or 50 b such that theshutter member 5 a or 5 b can be turned between the covered anduncovered positions of the opening 44, as shown in FIGS. 10 and 11. Atthe end of the guide slot 54 near the outer perimeter of the inner rotor4, there are formed an engagement hole 55 and an elastic pushing piece56. When the shutter member 5 a or 5 b is in the covered positionthereof, the guide pin 53 of the lower shell 7 will be engaged in theengagement hole 55 and at the same time the elastic pushing piece 56will push the guide pin 53 engaged in the engagement hole 55.

[0086] Note that as shown in FIG. 5, a dustproof rib 57 is formed allaround the opening 24 in the lower shell 7 as well as along extensionsof lateral edges of the opening 24 to prevent dust or the like fromentering the cartridge 1. The dustproof rib 57 includes auxiliary ribs57 a, 57 b, 57 c and 57 d whose end portions joining the outer wall 21of the lower shell 7 are as high as the outer wall 21. When the shuttermembers 5 a and 5 b cover the opening 44, the dustproof rib 57 isengaged in dustproof recesses 58 formed in the shutter members 5 a and 5b, respectively. As shown in FIGS. 12 and 13, the inner rotor 4 has alsoformed in the vicinity of each of the pair of pivots 49 a and 49 bthereof a disengagement projection 59 which cancels the engagementbetween the dustproof rib 57 and dustproof recesses 58. Each of thesedisengagement projections 59 in pair is formed as generally high as thedustproof rib 57. When the shutter member 5 moved from the positionwhere it covers the opening 44 to the position where it uncovers theopening 44, the disengagement projection 59 cancels the engagementbetween the dustproof rib 57 and dustproof recesses 58.

[0087] As shown in FIGS. 10 and 11, each of the pair of shutter members5 a and 5 b has formed thereon a first engagement piece 60 a and secondengagement piece 60 b. When the pair of shutter members 5 a and 5 b isin the position where they cover the openings, the first engagementprojection 60 a engages on the auxiliary ribs 57 a and 57 c included inthe dustproof rib 57, while the second engagement projection 60 bengages on the other auxiliary ribs 57 b and 57 d. Each of the pair ofshutter members 5 a and 5 b has formed in the free end portion of thesecond engagement portion 52 thereof a cut 61 in which the auxiliaryribs 57 b and 57 d included in the dustproof rib 57 are engaged.

[0088] The cartridge 1 constructed as having been described above isassembled as will be described below:

[0089] To assemble the cartridge 1, the upper shell 6 is first placedwith the inner surface being directed upward, and then the ring portion43 of the inner rotor 4 is engaged in the guide recess 13 of the uppershell 6. The inner rotor 4 should be pre-positioned in relation to theupper shell 6 such that the opening 44 in the inner rotor 4 and thefirst and second pickup access openings 9 and 12 in the upper shell 6are aligned with each other.

[0090] Next, the pair of shutter members 5 a and 5 b is installed to theinner rotor 4. More specifically, with the pair of shutter members 5 aand 5 b being butted at the butting faces thereof to each other, thepivots 49 a and 49 b of the inner rotor 4 are engaged into theengagement holes 50 a and 50 b. Thereby, the shutter members 5 a and 5 bin pair are installed to be pivotable about the pivots 49 a and 49 b,respectively, of the inner rotor 4. The pair of shutter members 5 a and5 b is pre-positioned in relation to the inner rotor 4 so that thebutting faces of the pair of shutter members 5 a and 5 b come to theedges of the opening 44 in the inner rotor 4. At the same time or beforeor after the pre-positioning, the locking member 29 the pivot 25 on thelower shell 4 is inserted in the engagement hole 31 in the lockingmember 29 is installed, and also the write protection member 30 isdisposed in position.

[0091] Next, the lower shell 7 is joined to the upper shell 6. Morespecifically, with the outer walls 8 and 21 of the upper and lowershells 6 and 7, respectively, being butted to each other, thepositioning wall 22 of the lower shell 7 is engaged in to thepositioning concavity 10 of the upper shell 6. Thus, the positioning cap28 at the lower shell 7 will be fitted on the coupling pin 20 at theupper shell 6. Also, the dustproof wall 23, lower corner wall 26 andrising lower wall 27 at the lower shell 7 will be engaged in the first,second and third recesses 16, 17 and 19, respectively, at the uppershell 6.

[0092] The guide pin 53 at the lower shell 7 will be engaged in theguide slot 54 in each of the shutter members 5 a and 5 b. Bypre-positioning the pair of shutter members 5 a and 5 b in relation tothe inner rotor 4, the lower shell 7 and pair of shutter members 5 a and5 b can easily be positioned in relation to each other at this time.Next, the set screw is screwed into the screw hole in the positioningpin 20 through the through-hole in the coupling cap 28. Thus, the lowershell 7 is joined to the upper shell 6 and thus the cartridge body 2 isformed. At this time, the inner rotor 4 and pair of shutter members 5 aand 5 b are in their respective positions where they do not cover theopenings 24 and 44, respectively.

[0093] Next, the geared portion 45 is operated to rotate the inner rotor4 in a direction of covering the openings 24 and 44, whereby the pair ofshutter members 5 a and 5 b will cover the opening 24 in the cartridgebody 2. With the above operations, the cartridge 1 is completelyassembled. As seen from the foregoing explanation, it will be clear thatthe cartridge 1 according to the present invention uses a reduced numberof parts and can be assembled extremely easily. Since no spring is usedas a part, the cartridge 1 can easily be assembled.

[0094] The lower shall 7 may be fixed to the upper shell 6 not only withthe aforementioned set screw, but the upper and lower shells 6 and 7 maybe joined integrally to each other with an adhesive, ultrasonic weldingor the like.

[0095] The cartridge 1 constructed as having been described in theforegoing is in a state as shown in FIGS. 1, 3 and 15. Moreparticularly, with the stop projection 33 a of the locking member 29being engaged in the second engagement concavity 42 of the inner rotor4, the pair of shutter members 5 a and 5 b is locked in the positionwhere they cover the openings 24 and 44. At this time, the firstengagement concavity 41 of the inner rotor 4 is exposed to outsidethrough the inner rotor access opening 35 b, and the opening projection32 a of the locking member 29 is exposed to outside through the lockingopening 35 a. When the cartridge 1 is loaded into the recorder/player,the shutter releasing mechanism at the recorder/player side will releasethe shutter locking so that the shutter members 5 a and 5 b can bepivoted. As shown in FIG. 16, the lift-up projection 14 slides onto thelift-up projection 48, so that the pair of shutter member 5 a and 5 bwill be caught at both the sides thereof between the inner rotor 4 andlower shell 7. Therefore, the pair of shutter members 5 a and 5 bpositively cover the openings 24 and 44 when the cartridge 1 is not inuse. In this condition, the optical disc 3 can be introduced into, orremoved from, the disc receptacle 11 a of the cartridge 1 through theinsertion/removal opening 2 a in the upper shell 6. Then the cartridge 1will have a user's desired optical disc 3 set therein and be loaded intothe recorder/player.

[0096] The cartridge 1 constructed as having been described in theforegoing is used being loaded in a disc recorder/player 70 shown inFIG. 17. The recorder/player 70 is designed to use a disc cartridgehaving pre-encased therein the optical disc 3 and thus has no discinsertion/removal opening 2 a formed in the upper shell 6. The cartridge1 according to the present invention can be loaded in thisrecorder/player.

[0097] The recorder/player 70 will be explained herebelow with referenceto FIG. 17. The recorder/player 70 includes a casing 71 having disposedtherein a main unit incorporating a loader for the cartridge 1. Thecasing 71 has formed in the front side thereof a disc slot 72 throughwhich the cartridge 1 is to be inserted. The disc slot 72 is closed by acover 73. When the cover 73 is pressed by the front end of the cartridge1, it is pivoted inwardly to uncover the disc slot 72. Thus, thecartridge 1 can be introduced into the disc loader in the casing 71.

[0098] The main unit disposed inside the casing 71 has a loadingmechanism to load the cartridge 1 into the disc loader, as shown in FIG.18. The cartridge 1, having been inserted first at the front end thereofinto the casing 71 through the disc slot 72, is automatically pulled tothe disc loader. The disc loader includes a disc rotation drivemechanism 74 to rotate the optical disc 3 at CLV (constant linearvelocity), CAV (constant angular velocity) or at a combination of them,and optical pickup 75. The disc rotation drive mechanism 74 includes adisc table 76 installed to the drive shaft of a spindle motor rotatablywith the drive shaft, a clamping plate to catch the optical disc 3 androtate the optical disc along with the disc table 76. When the cartridge1 is inserted into place in the disc loader, the disc table 76 will beengaged in a central hole 3 a of the optical disc 3 while holding theoptical disc 3 in cooperation with the clamping plate. Once the spindlemotor is put into run, the disc table 76 rotates the optical disc 3 atCLV or CAV.

[0099] The optical pickup 75 converges a light beam of about 400 nm inwavelength, emitted from a semiconductor laser, through an objectivelens, and focuses the light beam on the signal recording surface of theoptical disc 3 to write information signal to the optical disc 3, anddetects a return light reflected from the signal recording surface toread information signal from the optical disc 3.

[0100] The disc loader in the recorder/player 70 includes a shutterreleasing member 80 included in a shutter releasing mechanism whichrotates the inner rotor 4 when the cartridge 1 is set in the disc loaderand pivots the shutter members 5 a and 5 b. As shown in FIG. 19, theshutter releasing member 80 includes a rack 81 which is to be in meshwith the geared portion 45 of the inner rotor 4, a first engagementprojection 82 provided at the end of the rack 81 for initial operationof the inner rotor 4, a second engagement projection 83 provided at thebase of the track 81 for stopping the inner rotor 4, etc. The rack 81has generally as many teeth as the geared portion 45 has.

[0101] The first engagement projection 82 is provided at the end of afirst elastic member 84 provided at one end of the rack 81, and thesecond engagement projection 83 is provided at the end of a secondelastic member 85 provided at the other end of the rack 81, such thatthey can positively be engaged in the engagement concavities 41 and 42,respectively, in the inner rotor 4. Such a shutter releasing member 80may be adapted to move straight in relation to the cartridge 1 set inthe disc loader and operate the shutter members 5 a and 5 b.Alternatively, the shutter releasing member 80 may be fixed to the mainunit to operate the shutter members 5 a and 5 b as the cartridge 1 ismoved to the disc loader.

[0102] The cartridge 1 is inserted into the disc slot 72 while pushingat the front end thereof the cover 73 as shown in FIG. 18. Once thecartridge 1 is inserted, the shutter members 5 a and 5 b are pressed bythe cartridge 1 to start being released or opened. First, the shutterreleasing member 80 is engaged in the guide recess 36 in the cartridge 1and the first engagement projection 82 presses the opening projection 32a of the locking member 29, accessible from outside through the lockingopening 35 a formed in the guide recess 36, as shown in FIG. 20. Thus,the locking member 29 pivots about the pivot 25 and stop projection 33 ais disengaged from the second engagement concavity 42 in the inner rotor4. As a result, the inner rotor 4 is unlocked and thus enabled torotate.

[0103] When the shutter releasing member 80 further moves ahead of thecartridge 1, the rack 81 will continuously press the operatingprojection 32 a of the locking member 29, thereby keeping the innerrotor 4 unlocked. As shown in FIG. 22, the first engagement projection82 is engaged in the first engagement concavity 41 exposed to outsidethrough the inner rotor access opening 35 b of the inner rotor 4 to putthe inner rotor 4 in a ready state for rotation. The shutter releasingmember 80 further moves ahead of the cartridge 1 to pivot the innerrotor 4. At this time, the lift-up projections 14 and 48 are disengagedfrom each other as shown in FIG. 21 and thus the friction is reduced,and hence the inner rotor 4 can smoothly be rotated with a small force.The rack 81 of the shutter releasing member 80 is put in mesh with thegeared portion 45 exposed to outside through the inner rotor accessopening 35 b as shown in FIG. 22.

[0104] Having further moved ahead of the cartridge 1, the shutterreleasing member 80 having the rack 81 thereof put in mesh with thegeared portion 45 of the inner rotor 4 rotates the inner rotor 4 asshown in FIG. 23. Thus, the guide pin 53 of the inner rotor 4 is engagedin the guide hole 54 so that the shutter members 5 a and 5 b pivoted tothe pivots 49 a and 49 b, respectively, will pivot in a direction ofuncovering the openings 24 and 44. When the rack 81 of the shutterreleasing member 80 is disengaged from the geared portion 45 of theinner rotor 4, the shutter members 5 a and 5 b stop pivoting as shown inFIG. 24, and then the second engagement projection 83 of the shutterreleasing member 80 is engaged in the second engagement concavity 42 ofthe inner rotor 4. Thus, the shutter members 5 a and 5 b are kept tofully uncover the openings 24 and 44.

[0105] Thereafter, the disc table 76 included in the disc rotation drivemechanism 74 enters through the opening 24 b, is engaged into thecentral hole 3 a of the optical disc 3 and cooperates with the clampingplate to clamp the optical disc 3 rotatably. Next, the optical pickup 75enters through the opening 24 a. Thus, the optical disc 3 is rotated bythe disc rotation drive mechanism 74. A light beam is projected from theoptical pickup 75 to the optical disc 3 at the signal recording surfacethereof for writing information signal to the optical disc 3. A returnlight reflected from the signal recording surface is detected forreading information signal from the optical disc 3.

[0106] On the other hand, to remove the cartridge 1 from inside therecorder/player 70, the user operates the eject button included in acontrol unit, for example, provided on the recorder/player. Thus, theloading mechanism ejects the cartridge 1. The cartridge 1 will move tothe disc slot 72, while the aforementioned shutter releasing member 80will correspondingly retreat in relation to the cartridge 1. Along withthe retreat of the shutter releasing member 80, the inner rotor 4 andpair of shutter members 5 a and 5 b will reversely take the steps theyhave taken for inserting the optical disc. That is, the inner rotor 4will rotate reversely and the pair of shutter members 5 a and 5 b willcover the opening 24 in the cartridge body 2.

[0107] The cartridge 1 permits the user to freely replace the opticaldisc 3 through the disc insertion/removal opening 2 a formed in the mainside of the upper shell 6. Since the cartridge 1 receives the opticaldisc 3 through the insertion/removal opening 2 a with the signalrecording surface being directed down, it is possible to prevent anyfingerprint or the like from adhering to the signal recording surface ofthe optical disc 3 being handled. The cartridge 1 permits to use theoptical disc 3 normally used, not encased in any cartridge or the like,in a recorder/player 70 dedicated for a disc cartridge including thecommon parts such as the inner rotor 4, shutter members 5 a and 5 b,locking members 29, etc. the cartridge 1 and of which the optical discpre-encased therein can not be replaced with another. Since thecartridge 1 can be produced following almost same manufacturingprocedure for a disc cartridge, it can be manufactured in a disccartridge production line.

[0108] Note that as shown in FIG. 25, a come-off preventive mechanism 91may be provided in a plurality of places around the insertion/removalopening 2 a of the upper shell 6 included in the cartridge 1 to preventthe optical disc 3 held in the disc receptacle 11 a from coming off. Thecome-off preventive mechanism 91 is provided in three places around theinsertion/removal opening 2 a. Each of the come-off preventivemechanisms 91 is formed integrally with the opening wall 11 as shown inFIG. 26 to avoid an increased number of cartridge parts. The come-offpreventive mechanism 91 includes a come-off preventive piece 92 toprevent the optical disc 3 held in the disc receptacle 11 a from comingoff, and elastically flexible pieces 93 to couple the come-offpreventive piece 92 and opening wall 11 with each other. The come-offpreventive piece 92 is provided projecting toward the perimeter of theinsertion/removal opening 2 a to catch the perimeter of the optical disc3 held in the disc receptacle 11 a. The end top of the come-offpreventive piece 92 is tapered, and the tapered end top serves as aninsertion guide 94 to guide the optical disc 3 being inserted into thedisc receptacle 11 a. The two elastically flexible pieces 93 areprovided across the come-off preventive piece 92 to couple the latter tothe opening wall 11. When inserting the optical disc 3, the elasticallyflexible pieces 93 will be moved outwardly of the disc receptacle 11 aand the come-off preventive piece 92 move toward the perimeter of theinsertion/removal opening 2 a, thus permitting to receive the opticaldisc 3 in the disc receptacle 11 a.

[0109] As shown in FIG. 27, when the optical disc 3 is inserted into thedisc receptacle 11 a, the insertion guide 94 is pressed by the perimeterof the optical disc 3 in the direction of arrow Y₁ in FIG. 27. Morespecifically, when the insertion guide 94 is pressed in the direction ofarrow Y₁ in FIG. 27, the elastically flexible pieces 93 are elasticallymoved in the direction of arrow X₁ in FIGS. 26 and 27, and thus thecome-off preventive piece 92 is provisionally moved toward the perimeterof the insertion/removal opening 2 a against the elasticity of theelastically flexible pieces 93. Thus, the optical disc 3 falls into thedisc receptacle 11 a.

[0110] Note that the optical disc 3 will possibly have the signalrecording surface thereof stained and/or damaged if it is replacedrepeatedly too many times. On this account, the optical disc 3 oncereceived in the disc receptacle 11 a should desirably be not easilyremovable from the cartridge 1. To this end, the come-off preventivemechanism 91 to prevent at least the optical disc 3 from coming off isconstructed as follows. Namely, its end top is tapered as the insertionguide 94 and its surface for catching the optical disc 3 is made flat inparallel to the optical disc 3, so that once the optical disc 3 isreceived in the disc receptacle 11 a, the come-off preventive piece 92will not easily be movable toward the perimeter of the insertion/removalopening 2 a against the elasticity of the elastically flexible pieces 93and thus the optical disc 3 cannot easily be taken out of the discreceptacle 11 a.

[0111] Note that in the foregoing, the present invention has beenexplained concerning the embodiment thereof provided with the threecome-off preventive mechanisms 91 but the come-off preventive mechanism91 may be provided in one place, or in a plurality of places to preventthe optical disc 3 more positively from coming off.

[0112] The come-off preventive mechanism for the optical disc 3 receivedin the disc receptacle 11 a may be adapted as shown in FIGS. 28 to 30.As shown, the come-off preventive mechanism generally indicated with areference 101 is provided in three places around the insertion/removalopening 2 a. Each of the come-off preventing mechanisms 101 includes areceiver 102 formed in the wall of the insertion/removal opening 2 a anda come-off preventive member 103 received in the receiver 102. Thecome-off preventive member 103 is composed of a come-off preventivepiece 104 to catch the perimeter of the optical disc 3 held in the discreceptacle 11 a and thus prevent the optical disc 3 from coming from thedisc receptacle 11 a, elastically flexible pieces 105 to limit themovement of the come-off preventive member 103, and an operating piece106 to operate the come-off preventive member 103. The elasticallyflexible pieces 105 are formed to elastically move inwardly in thedirection of arrow X₂ in FIG. 29, and each of them has an engagementportion 107 provided on the free end thereof.

[0113] The receiver 102 to receive the come-off preventive member 103 isformed to such a size that the come-off preventive piece 104 projectstoward the insertion/removal opening 2 a and can be moved between acome-off preventive position in which it catches the perimeter of theoptical disc 3 held in the disc receptacle 11 a and a discinsertion/removal position where the come-off preventive piece 104retreats from the insertion/removal opening 2 a and the optical disc 3can be inserted or removed. The come-off preventive member 103 receivedin the receiver 102 has the operating piece 106 thereof exposed tooutside through an access hole 108 formed in the upper shell 6. Theengagement portion 107 of each elastically flexible piece 105 isselectively engaged in either a first engagement concavity 109 or secondengagement concavity 110 formed in the receiver 102. Between the firstand second engagement concavities 109 and 110, there is provided aprojection 111 which clicks when overridden by the engagement portion107.

[0114] In the come-off preventive mechanism 101, when the optical disc 3is inserted into, or removed from, the cartridge 1, the operating piece106 exposed to outside through the access hole 108 is moved toward thewall of the insertion/removal opening 2 a in the direction of arrow X₃in FIGS. 29 and 30 for engagement of the engagement portion 107 into thesecond engagement concavity 110. Thus, the come-off preventive member103 is held in the insertion/removal position where the come-offpreventive piece 104 has retreated from the insertion/removal opening 2a and the optical disc 3 can be inserted or removed. Namely, the opticaldisc 3 can be inserted into, or removed from, the cartridge 1. Once theoptical disc 3 is inserted into the disc receptacle 11 a, when theoperating piece 106 exposed to outside through the access hole 108 ismoved toward the insertion/removal opening 2 a, the engagement portion107 moves from the second engagement concavity 110 to the firstengagement concavity 109. When overriding the projection 111, theengagement portion 107 will click. When the engagement portion 107 isengaged in the first engagement concavity 109, the come-off preventivemember 103 is held in the come-off preventive position where thecome-off preventive piece 104 projects toward the insertion/removalopening 2 a. In case the come-off preventive mechanism 101 is providedin a plurality of places so that even if one of the come-off preventivemembers 103 is moved erroneously to the disc insertion/removal position,the other come-off preventive members 103 will stay in their respectivecome-off preventive positions, it is possible to prevent the opticaldisc 3 from erroneously coming from the disc receptacle 11 a.

[0115] The cartridge 1 may have provided on the cartridge body 2 thereofa cover which covers the disc insertion/removal opening 2 a to preventthe optical disc 3 received in the disc receptacle 1 a from coming off.More specifically, the upper shell 6 of the cartridge body 2 has a cover116 installed thereon as shown in FIGS. 31 and 32. The cover 116 isformed to have a generally same size as the insertion/removal opening 2a and has a rising wall 117 provided along the perimeter thereof. Such acover 116 is pivoted to a pivot 118 provided at the rear side of thecartridge body 2, and thus it is supported pivotally on the cartridgebody 2. When the cover 116 covers the insertion/removal opening 2 a, theopening wall 11 and rising wall 117 overlap each other, whereby anyforeign matter such as dust will not easily enter the disc receptacle 11a. The cover 116 may be adapted to be forced by an forcing means such asa spring in a direction of uncovering the insertion/removal opening 2 a.

[0116] Note that the cover 116 may has a window 134 which permits toview the optical disc 3 in the disc receptacle 11 a through it. Also,there may be provided on the cover 116 a marking 135 such as an arrow toindicate the direction of insertion of the cartridge 1 into therecorder/player 70.

[0117] As shown in FIGS. 31 to 34, the cartridge 1 according to thepresent invention has a locking mechanism 121 to hold the cover 116 in aposition where it covers the insertion/removal opening 2 a. The lockingmechanism 121 is provided in two places around the insertion/removalopening 2 a. Each of these locking mechanisms 121 includes a receiver122 formed in the wall of the insertion/removal opening 2 a and anoperating member 123 received in the receiver 122 to open and close thecover 116.

[0118] The cover operating member 123 consists of a tab 124 operable bythe user, a first elastically flexible piece 125 to lock the cover 116,and a second elastically flexible piece 126 to hold the operating member123 in a predetermined position.

[0119] The tab 124 is exposed to outside through a generally rectangularaccess hole 127 formed in the top of the upper shell 6. Also, the firstelastically flexible piece 125 has formed at the end thereof a lockingportion 129 which is engaged in an engagement hole 128 formed in therising wall 117 of the cover 116. Also, the second elastically flexiblepiece 126 has an engagement portion 130 formed at the end thereof. Theengagement portion 130 is selectively engaged in a first engagementconcavity 131 destined for holding the operating member 123 provided inthe receiver 122 in a locking position where the locking portion 129 isengaged in the engagement hole 128, and a second engagement concavity132 destined for holding the operating member 123 in an unlockingposition where the locking portion 129 having unlocked the cover 116 isnot engaged in the engagement hole 128. Between the first and secondengagement concavities 131 and 132, there is provided a projection 133which clicks when it is overridden by the engagement portion 130.

[0120] When the cover 116 is being locked to cover the insertion/removalopening 2 a, the locking portion 129 of the first elastically flexiblepiece 125 is engaged in the engagement hole 128 in the rising wall 117of the cover 116, while the engagement portion 130 of the secondelastically flexible piece 126 is engaged in the first engagementconcavity 131 to hold the operating member 123 in the locking position,as shown in FIG. 33. When the tab 124 exposed to outside through theaccess hole 127 is moved in the direction of arrow S₁ in FIG. 33 inorder to unlock the cover 116, the engagement portion 130 overrides theprojection 133 against the elasticity of the second elastically flexiblepiece 126 and gets engaged into the second engagement concavity 132,while the first elastically flexible piece 125 is moved toward the tab124 and the locking portion 129 gets disengaged from the engagement hole128, as shown in FIG. 34. At this time, the engagement portion 130overrides the projection 133 to click. Thus, the user can know that theoperating member 123 has been moved from one to another position. Thelocking mechanism 121 can be provided in a plurality of places. In thiscase, even when one of the operating members 123 is erroneously movedfrom the locking position to the unlocking position, the other operatingmembers 123 will stay in their respective locking positions to preventthe cover 116 from wrongly uncovering the insertion/removal opening 2 a,and thus the optical disc 3 will not come off the disc receptacle 11 a.It should be noted that near the access hole 127, there may be provideda marking 136 indicating a direction in which the operating member 123is to be moved, for example, an unlocking direction.

[0121] In the above embodiment, the opening 24 is formed to extend fromthe front toward the center of the cartridge body 2. However, thepresent invention can be applied to a cartridge 140 shown in FIGS. 35 to37. The cartridge 140 has formed therein an opening 141 extendinggenerally in parallel to the direction of insertion into therecorder/player 70 from the front to the rear thereof. Morespecifically, the opening 141 is formed in the bottom of the cartridge 1to have a generally rectangular shape extending from near the frontcenter to near the rear center of the lower shell 7. The front and rearportions of the opening 141 are used as write/read openings 141 a and141 b the optical pickup enters, and the central portion of the opening141 is used as a drive opening 141 c the disc rotation drive mechanismenters. The cartridge 140 has provided therein an inner rotor 142 havingformed therein an opening 143 corresponding to the opening 141 andhaving a generally same radial size as the opening 141. It should benoted that the other construction of this cartridge 140 is common tothat of the aforementioned cartridge 1 and so will not be explained indetail.

[0122] In the cartridge 140 loaded in the recorder/player, the shuttermembers 5 a and 5 b are opened by the shutter releasing mechanism of therecorder/player, thus the opening 141 is uncovered and the optical disc3 is exposed to outside. Then the optical disc 3 is clamped and rotatedby the disc rotation drive mechanism in the recorder/player, havingentered the cartridge 1 through the opening 141 c. Also, the opticalpickup enters the opening 141 a or 141 b. Projecting a light beam to theoptical disc 3, the optical pickup writes information signal to theoptical disc 3. projects a light beam to the optical disc 3. Detecting areturn light reflected from the signal recording surface of the opticaldisc 3, the optical pickup reads information signal from the opticaldisc 3. Since the cartridge 140 allows to use two optical pickups forwrite and read of information signal, it will make it possible to writeand read information signal in a reduced length of time.

INDUSTRIAL APPLICABILITY

[0123] According to the present invention, the cartridge has aninsertion/removal opening formed in the main side of the upper shell,through which a disc can be freely inserter into, or removed from, thecartridge. Therefore, the cartridge having a disc held in the cartridgebody thereof can be loaded into the recorder and/or player to writeinformation signal to the disc and also read information signal from thedisc. Since in the cartridge according to the present invention, thestructure including the shutter members etc. is common to arecording-medium cartridge (having a recording medium pre-encasedtherein), the cartridge can be loaded into a recorder and/or playerdedicated for use with such a recording-medium cartridge. Further, sincethe cartridge according to the present invention has the generally sameconstruction as that of the recording medium cartridge of which therecording medium pre-encased therein is not replaceable, it can easilybe manufactured using the same assembling line for the recording-mediumcartridge.

1. A cartridge comprising: a cartridge body consisting of an upper shellhaving a disc insertion/removal opening formed in the main side thereofand a lower shell, butted to each other to define a disc receptacle inwhich a disc is rotatably held, the lower shell having formed therein afirst opening through which a disc held in the disc receptacle is atleast partially exposed to output; a middle shell disposed rotatably inthe cartridge body to define the bottom of the disc receptacle by themain side thereof, having the main side thereof exposed to outsidethrough the insertion/removal opening in the upper shell, having formedin the main side thereof a second opening corresponding to the firstopening in the lower shell of the cartridge body and which is rotatablyreceived in the cartridge body; and a pair of shutter members whichuncovers the first and second openings when the middle shell rotatesuntil the first and second openings are aligned with each other.
 2. Thecartridge as set forth in claim 1, wherein there is provided around thedisc insertion/removal opening in the upper shell a disc come-offpreventive mechanisms to prevent a disc received in the disc receptaclethrough the insertion/removal opening from coming off; the come-offpreventive mechanism being composed of a disc insertion guide to guide adisc being inserted into the disc receptacle and a come-off preventivepiece to prevent the disc once received in the fisc receptacle fromcoming off, the come-off preventive piece being formed integrally oncontact with elastically flexible pieces which are elastically movedradially of the disc receptacle
 3. The cartridge as set forth in claim2, wherein the come-off preventive mechanism is provided in a pluralityof places around the insertion/removal opening in the upper shell. 4.The cartridge as set forth in claim 1, wherein there is provided aroundthe insertion/removal opening in the upper shell a disc come-offpreventive mechanisms; the come-off preventive mechanisms including acome-off preventive member received in a receiver formed in the wall ofthe insertion/removal opening in the upper shell to prevent a discreceived in the disc receptacle from coming off; the come-off preventivemember including elastically flexible pieces each having an engagementportion formed at one end thereof, and an operating piece to move thecome-off preventive piece between a come-off preventive position wherethe come-off preventive mechanism is to prevent the disc received in thedisc receptacle and an access position in which the disc is to beinserted and/or removed; and the receiver including a first engagementconcavity in which the engagement portion is engaged when the come-offpreventive mechanism holds the come-off preventive member in thecome-off preventive position, and a second engagement concavity in whichthe engagement portion is engaged when the come-off preventive mechanismholds the come-off preventive member in the access position.
 5. Thecartridge as set forth in claim 4, wherein the come-off preventivemechanism is provided in a plurality of places around theinsertion/removal opening in the upper shell.
 6. The cartridge as setforth in claim 1, wherein the cartridge body is provided with a cover touncover and cover the insertion/removal opening.
 7. The cartridge as setforth in claim 6, further comprises a locking mechanism to lock thecover in a closed position where the covers closes the insertion/removalopening; the locking mechanism including a cover operating memberdisposed in the receiver formed in the wall of the insertion/removalopening in the upper shell; the cover operating member including a firstelastically flexible piece having provided at an end thereof a lockingportion which is engaged on the engagement piece on the cover, a secondelastically flexible piece having an engagement portion provided at anend thereof, and an operating portion which moves the cover operatingmember between a locking position in which the locking portion isengaged on the engagement piece and an unlocking position in which thelocking portion is not disengaged on the engagement piece; and thereceiver including a first engagement concavity in which the engagementportion is to be engaged when the cover operating member is held in thelocking position, and a second engagement concavity in which theengagement portion is to be engaged when the cover operating member isheld in the unlocking position.
 8. The cartridge as set forth in claim7, wherein the locking mechanism is provided in a plurality of placesaround the insertion/removal opening.